code: def test_predict_seq():
      """[Sequential] Test multilayer prediction."""
      S = lc_s.predict(X)
      B = lc_b.predict(S)
      U = lc_u.predict(B)
      out = seq.predict(X)
      np.testing.assert_array_equal(U, out)
  
file_path: mlens/mlens/ensemble/tests/test_sequential.py
imports: import numpy
  from mlens.ensemble import SequentialEnsemble, SuperLearner, BlendEnsemble, Subsemble
  from mlens.ensemble.base import Sequential
  from mlens.testing.dummy import Data, PREPROCESSING, ESTIMATORS, ECM, EstimatorContainer
label_desc: Use image node_id 2 for calling a global function with example usage: test_predict_seq() without return types